A group mobile switchboard service allocates for a group customer a normal MSISDN (Mobile Station International ISDN (Integrated Services Digital Network) Number) as the group mobile switchboard number, and provides a service such as automatic switchboard, voice controlled switchboard, manual switchboard, etc., via the group mobile switchboard number, and also provides a service such as telephone number inquiry, telephone transfer, etc. After dialing the group mobile switchboard number, a calling party may dial an extension number (for an automatic switchboard) directly, say the called party's name (for a voice controlled switchboard) so as to be transferred to the extension subscriber, or connect to a manual agent (for a manual switchboard) to be transferred by an operator.
A subscriber-based ring back tone service is a service subscribed to by a called party, which provides a calling party a piece of pleasant music or greetings instead of a normal ring back tone during a call. After a subscriber-based ring back tone service has been activated upon application of a customer, the customer may subscribe to a subscriber-based ring back tone individually such that when he is called, the subscribed personalized music or record will be played for the calling party, instead of a normal ring back tone. When the called party is in a non-idle status, such as being busy, out of service, power off, etc., an original voice message provided by the network system will still be played.
A current ring back tone service based on a group mobile switchboard service (i.e., a group ring back tone service) is an extension of the subscriber-based ring back tone described above, which is mainly for a group customer, provides a group ring back tone related to the group according to the group customer's requirement, and allows each of the customers in the group who have applied for a subscriber-based ring back tone to set the group ring back tone as his own subscriber-based ring back tone, according to the requirement of the group customer, or sets the group ring back tone provided by the group customer as a default ring back tone for every customer in the group in a specified period of time according to the requirement of the group customer.
To implement a subscriber-based ring back tone service and a group ring back tone service based on an intelligent network, equipment in a mobile intelligent network, such as a Service Control Point (SCP), an Intelligent Peripheral (IP), etc., is needed. Referring to FIG. 1, there is shown a schematic diagram illustrating a current networking architecture for implementing a ring back tone service based on a mobile intelligent network, wherein T-CSI (Terminating CAMEL (Customized Applications for Mobile network Enhanced Logic) Subscription Information) is registered for a called number (a personal mobile number or a group mobile switchboard number) in a Home Location Register (HLR) 1; when a calling party calls a called party which has subscribed to a ring back tone service, a Gateway Mobile Switching Center (GMSC)/Mobile Switching Center (MSC) 2 which triggers the intelligent service will trigger a mobile terminated of the intelligent service for the called party to a home SCP 3 of the called party; the SCP 3 instructs the GMSC/MSC 2 to connect the call to a ring back tone IP 4, and establishes a call connection with the called party through a bridging function of the ring back tone IP 4; the ring back tone IP 4 plays a group ring back tone subscribed to by the group which the called party belongs to or a subscriber-based ring back tone subscribed to by the called party individually, and blocks a normal ring back tone sent by a visited MSC 5 of the called party.
FIG. 2 is a current signaling processing flow of implementing a ring back tone service based on a mobile intelligent network, the detailed process of which is as follows.
1. When a calling party calls a called party who has subscribed to a ring back tone, a GMSC/MSC which triggers the intelligent service sends Send Routing Information (SRI) to an HLR of the called party, and the HLR returns Send Routing Information acknowledge (SRI_ack) to the GMSC/MSC which triggers the intelligent service, wherein the SRI_ack message includes registered T-CSI, and by sending an Initial Detect Point (IDP) message, the GMSC/MSC triggers a mobile terminated of the intelligent service to a home SCP of the called party.
2. When determining that the called party has subscribed to a ring back tone, the home SCP of the called party sends an SRI message to the HLR of the called party, and the HLR of the called party returns an SRI_ack massage bearing a Mobile Station Roaming Number (MSRN) of the called party.
3. The home SCP of the called party sends an RRBE (Request Report BCSM (Basic Call State Model) Event) message to the GMSC/MSC which triggers the intelligent service, requesting the GMSC/MSC to monitor an event such as abandoning of the calling party, hanging up, no answer from the called party, routing selection failure, etc.
4. The home SCP of the called party sends an Apply Charging (AC) message to the GMSC/MSC which triggers the intelligent service, instructing the GMSC/MSC to monitor talk time.
5. The home SCP of the called party sends a CONNECT message to the GMSC/MSC which triggers the intelligent service, instructing the GMSC/MSC to connect to a ring back tone IP; wherein the parameters included in the CONNECT message are shown in the following table:
Name of information unitValue or description of(parameter)Meaning of parameterparameterdestinationRoutingAddressDestination routing address: theThe routing information forGMSC/MSC replacing theconnecting to the IP + thecalled number during a callcalled party's MSRNwith this parameterredirectingPartyIDRedirecting number: theThe called party's MSISDNGMSC/MSC replacing theredirecting number during a callwith this parameterredirectionInformationRedirection Information: theCause and times ofGMSC/MSC replacing theforwardingredirection information during a00110011, 00110001call with this parameteroriginalCalledPartyIDOriginal called party's number:The called party's MSISDNthe GMSC/MSC replacing theoriginal called party's numberduring a call with thisparameter
6. the GMSC/MSC which triggers the intelligent service sends an Initial Address Message (IAM) to the ring back tone IP, according to “the routing information for connecting to the IP”, which is included in the destination routing address in the received CONNECT message, so as to route the call to the ring back tone IP.
7. The ring back tone IP removes such parameters as the routing information before the subscriber's MSRN, original called party's number, redirecting number, redirection information, etc., and then sends the IAM to the visited MSC of the called party, so as to continue to connect the call to the visited MSC of the called party.
8. After being connected to the called party, the visited MSC of the called party rings for the called party, and plays a normal ring back tone for the calling party by returning an Address Complete Message (ACM) to the ring back tone IP.
9. After receiving the ACM, the ring back tone IP blocks the normal ring back tone sent from the visited MSC of the called party, and plays a ring back tone subscribed to by the called party for the calling party according to the called party's MSISDN by sending an ACM to the GMSC/MSC which triggers the intelligent service; and the calling party receives the ring back tone.
10. After the called party has answered, the visited MSC of the called party sends an Answer message (ANM) to the ring back tone IP.
11. After receiving the ANM, the ring back tone IP stops playing the ring back tone, and sends an ANM to the GMSC/MSC which triggers the intelligent service; a talk between the calling and called parties begins.
12. The calling party hangs up or the called party hangs up, and the talk is over; FIG. 2 shows the signaling process in the case that the called party hangs up.
However, the above process of implementing a ring back tone service based on a mobile intelligent network can only implement the function that the network system plays a subscriber-based ring back tone subscribed to by a called party for a calling party when the calling party dials a personal mobile number; it can not implement the function that the network system plays for a calling party a group ring back tone which is subscribed to for a group mobile switchboard number during the transfer from the switchboard to an extension, when the calling party calls a subscriber in the group by dialing the group mobile switchboard number, i.e., it can not implement the function of playing a ring back tone which is subscribed to correspondingly to a called umber for a calling party when the called number is used as a relay number for transfer.